German Patent Specification DE 10 2008 051 100 A1 discloses a clutch device. In this friction clutch, an operating point that changes due to wear on the friction linings is automatically readjusted. A spindle drive is provided on the pressure plate to rotate the ramp ring in one direction in the case of wear. For this purpose, a pawl is fixedly arranged on the housing. When a predetermined amount of wear is exceeded, the pawl rotates a pinion of the spindle drive before the friction clutch is disengaged by creating a form-locking connection between the pinion and the pawl. As the friction clutch is being disengaged, the operating point is corrected by a rotation of the pinion caused by the pawl. This method only provides discontinuous step-by-step compensation of the friction lining wear.
Non-published German Patent Application No. 10 2010 052 021.7 furthermore discloses a friction clutch with a readjustment device where the sensing and actuating device consisting of a pawl and a pinion is replaced by a wrap rope connected to the housing and wrapped around the spindle of the spindle drive. The wrap rope rotates the spindle of the spindle drive as a function of the wear on the lining to correct the operating point, which has changed due to lining wear, in a continuous and infinitely variable way. An operating point that changes in both directions, for example in one direction due to lining wear and in the other direction due to swelling friction linings and/or potting of the pressure plate and/or counter pressure plate, cannot be completely corrected.